Gospel, Gospels, evangel -- (the four books in the New Testament (Matthew, Mark, Luke, and John) that tell the story of Christ's life and teachings)
gospel, gospel truth -- (an unquestionable truth; "his word was gospel")
gospel, gospel singing -- (folk music consisting of a genre of a cappella music originating with Black slaves in the United States and featuring call and response; influential on the development of other genres of popular music (especially soul))